By the 17th century, English-language records had settled on a handful of stable anglicised forms of Ó Dubhda. The Fiants of Queen Elizabeth I, a principal source for Tudor-era Gaelic surnames, record spellings including O Dowde, O Dowda, and O Dowdie for members of the sept in the later 16th century. A Fiant of 1595 records the election of Dubhaltach Mac Ruaidhri Ui Dhubhda as Taoiseach — the last formally documented inauguration of an O’Dubhda chief under Gaelic custom (Mac Hale 1990).

Over the following two centuries the final -a of O’Dowda was progressively dropped in English-language records. By the time of Griffith’s Valuation (1848–64), O’Dowd had become the dominant anglicised form in the records of the heartland.

Griffith’s Valuation records the heaviest concentration of O’Dowd households in the baronies of Tireragh in County Sligo and Tirawley and Erris in north-west Mayo — the ancient territory of Tír Fhiachrach Muaidhe. These are the lands described in Mac Firbis’s Genealogies of Hy-Fiachrach as the patrimony of the sept, and the same territory treated in Mac Hale’s O’Dubhda Family History (1990).

The 1901 and 1911 censuses record O’Dowd households in every county of Ireland, with the highest numbers still in the Mayo–Sligo heartland and secondary concentrations in Dublin and the other major cities, reflecting 19th- and 20th-century rural-to-urban migration.

The Cromwellian confiscations of the 1650s transferred most O’Dowd-held lands to new proprietors; the Books of Survey and Distribution, compiled in the following decades, record the resulting ownership. The Williamite settlement of the 1690s completed the dispossession. From the early 18th century the family survived primarily as tenants in what had been their own territory.

Earlier versions of this page carried a dramatic account of “the last chief” being killed at the Battle of the Boyne in 1690. We have not been able to trace this to any primary or scholarly source, and have removed it. If any reader can provide a documentary reference, we would be glad to hear from them.

Emigration records from the 1830s onward show O’Dowd and Dowd families settling across the Irish diaspora — principally in Britain, North America, and Australia. No comprehensive published surname-geography study of O’Dowd exists; diaspora families are most reliably linked back through Irish parish registers (irishgenealogy.ie) and the Irish civil records of the late 19th century.